Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2006
Forfattere
Holger LangeSammendrag
Most phenomena in ecosystem research are assessed via repeated measurements of environmental variables. The dynamics of these time series is investigated with a variety of statistical techniques; in this article, we focus on modern nonlinear methods. They enable separation of short- and long-term components, show all types of trends and quantify the information contained and the complexity of the data sets.
Sammendrag
The aim of this three-year study (2001"2003) was to optimize fungicide application against anthracnose (Colletotrichum acutatum) in sweet and sour cherry orchards. The experimental sprays were applied to trees receiving normal fungicide programmes (grower schedule), although without the use of dithianon, except for the first year where only the experimental applications were applied to the sour cherry trees. Fungicide treatments were applied with either dithianon or copperoxychloride added prior to flowering or with dithianon added after flowering. Spraying with dithianon or copperoxychloride prior to flowering did not significantly reduce anthracnose compared to untreated. Two applications with dithianon during the green fruit stage (from petal fall and during the following 3"4 weeks) greatly reduced anthracnose at harvest. Three applications on green fruit did not reduce disease more than two applications. In sweet cherries, two sprays with dithianon at the green fruit stage in addition to the grower schedule reduced anthracnose at harvest from 14% to 3% in 2002 and from 15% to 1% the following year. In 2001, when very few fruit developed anthracnose, no treatment effects were evident. Treatments on green sour cherry fruit similar to those on sweet cherries reduced the attack of anthracnose from 85% to 42% in 2002 and from 51% to 12% the following year. In 2001, no treatment included only sprays on green fruit. However, one treatment, which included copperoxychloride at bud burst, one application of dithianon during flowering and two applications on green fruits, reduced anthracnose from 27% to 9%. Based on these results, cherry growers are recommended to spray twice with dithianon on green fruit if they have a history of anthracnose in their orchards.
Forfattere
Tor LunnanSammendrag
Timoteisortane ‘Engmo’, ‘Vega’ og ‘Noreng’ og foredlingslinjene ‘GpTi8905’, ‘LøTi8801’ og ‘LøTi9001’ er testa i reinbestand på åtte felt i Nord-Noreg og i fjellbygdene på Austlandet i tidsrommet 1999-2005. Alle sortane viste seg å vera tilstrekkeleg hardføre i prøvetida. Det var ikkje sikker forskjell mellom sortar i avling i førsteslåtten, medan ‘Vega’ og ‘Noreng’ hadde størst gjenvekst. Det var liten forskjell i fordøyelegheit mellom sortane. Fiberkvaliteten målt på NIRS kalibrert etter totalt ufordøyeleg NDF målt med in sacco-metoden var dårlegast hos ‘Vega’. ‘Noreng’ hadde bra fiberkvalitet, men lågare innhald av vassløyseleg karbohydrat enn ‘Engmo’. Forsøket viser at forskjellen mellom nordlege sortar og foredlingslinjer av timotei er liten, og at det derfor bør vera nok med ein nordleg sort i marknaden.
Forfattere
Magnus Karlsson Ari M. Hietala Harald Kvaalen Halvor Solheim Åke Olson Jan Stenlid Carl Gunnar FossdalSammendrag
Norway spruce (Picea abies (L.) Karst.) has a natural distribution in the northern parts of Europe and Asia and is economically the most important tree species grown in the Nordic countries. A common threat to Norway spruce is the basidiomyceteous fungus Heterobasidion parviporum Niemelä and Korhonen. H. parviporum mainly attacks Norway spruce, although Siberian fir (Abies sibirica Ledeb.) and Scots pine (Pinus sylvestris L.) occasionally get infected. One obstacle to studying host/pathogen interaction in conifers has been the limited availability of mature clones for controlled inoculations, as genetic variation within the host material and the lack of replicates complicate interpretation of the results. Somatic embryogenesis, rooted cuttings, and tissue cultures may provide solutions for this problem. Tissue cultures from mature Norway spruce trees have been proposed as a possible model system for assessing resistance toward fungal pathogens. Recent data on chitinase isoform activity in the Norway spruce/H. parviporum pathosystem are encouraging; clonal variation was observed in the isoforms affected by inoculation, and the isoforms showing increased band intensity following bark inoculation by H. parviporum were also induced in the inoculated tissue cultures of the corresponding clones. To investigate the biological relevance of tissue cultures in host-pathogen interaction studies, transcript levels of selected host and pathogen genes in tissue cultures of Norway spruce were compared to those in bark of 33-year-old ramets of the same clones upon challenge by the pathogenic fungus H. parviporum. Similar transcript profiles of the pathogen and host genes were observed in both tissues, this supporting the use of tissue cultures as experimental material for the pathosystem. Higher transcript levels of the host genes phenylalanine ammonia lyase, peroxidase, and glutathione-S-transferase were observed in the more resistant clone #589 than in the less resistant clone #409 during the early stages of colonization. The most striking difference between the spruce clones was related to gene transcript levels of a class IV chitinase, which showed a continuous increase in clone #409 over the experimental period, with a possible association of this gene product to programmed cell death. Several of the fungal genes assayed were differentially expressed during colonization, including putative glutathione-S-transferases, laccase, cellulase, cytochrome P450 and superoxide dismutase genes. The transcriptional responses suggest an important role for the antioxidant systems of both organisms.
Forfattere
Trygve S. AamlidSammendrag
Denne artikklen gir en oversikt over utviklinga arealer og avlingsnivå i norsk frøavl de siste ti åra. Framtidige forskingsoppgaver blir diskutert.
Sammendrag
I slutten av august 2006 vart det funne omfattande skade på blad av hestekastanje (Aesculus hippocastanum) ved fleire lokalitetar på Austlandet. Skadane skuldast bladflekksoppen Guignardia aesculi og mjøldoggsoppen Erysiphe flexuosa.
Sammendrag
På ettersommaren 2006, vart det funne to nye soppsjukdomar i norske grøntanlegg. Den eine sjukdomen var mjøldogg (Microsphaera syringae syn. Erysiphe syringae) på syrin ved fleire lokalitetar i Oslo, Akershus, Buskerud og Telemark. Den andre var Guignardia aesculi ("leaf blotch" på engelsk) på blad av hestekastanje i Horten, Tønsberg og Sandefjord. Byrjande angrep vart også registrert i planteskulen ved UMB på Ås.
Forfattere
Hege StubberudSammendrag
Det er ikke registrert sammendrag
Forfattere
Nils Øyvind Bergset Klaus Mittenzwei Viil Søyland Anders Nordlund Ivar PettersenSammendrag
Formålet med dette notatet er å belyse mulige effekter av økte tollkvoter på det norske markedet med bakgrunn i de pågående forhandlingene i WTO. En tollkvote er definert som en toll i to lag. I en gitt periode (gjerne ett år) benyttes en lav kvotetoll (toll innenfor tollkvoten) for et bestemt volum, og for det overskytende volumet innenfor perioden benyttes en høyere toll (toll over tollkvoten). Notatet gir en oversikt over teorien knyttet til denne problemstillingen, importen via tollkvoter til Norge og gir en del eksempler på hvilke følger import har fått på norsk produksjon og prisnivå. I Uruguayrunden ble det lagt inn krav om å bevare eksisterende markedsadgang og å sikre en minimumsadgang gjennom tollkvoter. I julirammeverket fra 2004 ble det bestemt at en kan få lavere krav om tollreduksjoner på sensitive produkter mot at en aksepterer tollkvoter på disse produktene. Skal det ha noen hensikt å definere varer som sensitive, må det ligge en gevinst i dette i forhold til det generelle regimet knyttet til tollreduksjoner. Økonomisk teori og empirisk erfaring tilsier at matvarer som importeres med bakgrunn i tollkvoter påvirker markedspris og omsatt mengde. Alt annet likt, øker matvareimport det samlede innenlandske tilbudet og resulterer dermed i større etterspørsel til en lavere markedspris. Tollkvoter som ikke utnyttes har ingen direkte innvirkning på markedet. […]
Sammendrag
In spring 2002, extensive damage was recorded in southeast Norway on nursery-grown Norway spruce seedlings that had either wintered in nursery cold storage or had been planted out in autumn 2001. The damage was characterised by a top shoot dieback. Two visually distinct types of necroses were located either on the upper or lower part of the 2001-year-shoot. Isolations from the upper stem necroses rendered Gremmeniella abietina, while Phomopsis sp. was isolated mostly from the lower stem necroses. RAMS (random amplified microsatellites) profiling indicated that the G. abietina strains associated with diseased nursery seedlings belonged to LTT (large-tree type) ecotype,and inoculation tests confirmed their pathogenicity on Norway spruce seedlings. Phomopsis sp. was not pathogenic in inoculation tests, this implying it may be a secondary colonizer. We describe here the Gremmeniella – associated shoot dieback symptoms on Norway spruce seedlings and conclude that the unusual disease outburst was related to the Gremmeniella epidemic caused by the LTT ecotype on large Scots pines in 2001. The role of Phomopsis sp. in the tissue of diseased Norway spruce seedlings is yet unclear.